Variable orifice bypass plunger

ABSTRACT

An improved plunger mechanism apparatus has a manually adjustable bypass valve to increase well flow production levels in high liquid wells. The plunger&#39;s descent rate can be fine tuned in the field by adjusting the orifice opening so that liquid can optimally flow through the plunger core during descent. Efficiency of well flow is increased by the addition of a variable bypass orifice, which can be preset in numerous positions to vary the amount of liquid bypass allowed depending on the well loading parameters. The plunger mechanism of the present invention allows numerous bypass set positions, which can be tuned at a well site and later changed as a function of future well loading parametric changes.

CROSS REFERENCE APPLICATIONS

This application is a non-provisional application claiming the benefitsof provisional application No. 60/563,711 filed Apr. 20, 2004.

FIELD OF THE INVENTION

The present invention relates to an improved plunger lift apparatus forthe lifting of formation liquids in a hydrocarbon well. Morespecifically the improved plunger consists of a variable orifice in abypass plunger apparatus that operates to allow a variation in plungerbypass capabilities as a function of well parameters.

BACKGROUND OF THE INVENTION

A plunger lift is an apparatus that is used to increase the productivityof oil and gas wells. In the early stages of a well's life, liquidloading is usually not a problem. When rates are high, the well liquidsare carried out of the well tubing by the high velocity gas. As the welldeclines, a critical velocity is reached below which the heavier liquidsdo not make it to the surface and start to fall back to the bottomexerting back pressure on the formation, thus loading up the well. Abasic plunger system is a method of unloading gas in high ratio oilwells without interrupting production. In operation, the plunger travelsto the bottom of the well where the loading fluid is picked up by theplunger and is brought to the surface removing all liquids in thetubing. The plunger also keeps the tubing free of paraffin, salt orscale build-up. A plunger lift system works by cycling a well open andclosed. During the open time a plunger interfaces between a liquid slugand gas. The gas below the plunger will push the plunger and liquid tothe surface. This removal of the liquid from the tubing bore allows anadditional volume of gas to flow from a producing well. A plunger liftrequires sufficient gas presence within the well to be functional indriving the system. Oil wells making no gas are thus not plunger liftcandidates.

As the flow rate and pressures decline in a well, lifting efficiencydeclines geometrically. Before long the well begins to “load up”. Thisis a condition whereby the gas being produced by the formation can nolonger carry the liquid being produced to the surface. There are tworeasons this occurs. First, as liquid comes in contact with the wall ofthe production string of tubing, friction occurs. The velocity of theliquid is slowed, and some of the liquid adheres to the tubing wall,creating a film of liquid on the tubing wall. This liquid does not reachthe surface. Secondly, as the flow velocity continues to slow, the gasphase can no longer support liquid in either slug form or droplet form.This liquid along with the liquid film on the sides of the tubing beginto fall back to the bottom of the well. In a very aggravated situationthere will be liquid in the bottom of the well with only a small amountof gas being produced at the surface. The produced gas must bubblethrough the liquid at the bottom of the well and then flow to thesurface. Because of the low velocity very little liquid, if any, iscarried to the surface by the gas. Thus, as explained previously, aplunger lift will act to remove the accumulated liquid.

A typical installation plunger lift system 100 can be seen in FIG. 1.Lubricator assembly 10 is one of the most important components ofplunger system 100. Lubricator assembly 10 includes cap 1, integral topbumper spring 2, striking pad 3, and extracting rod 4. Extracting rod 4may or may not be employed depending on the plunger type. Containedwithin lubricator 10 is plunger auto catching device 5 and plungersensing device 6. Sensing device 6 sends a signal to surface controller15 upon plunger 200 arrival at the well-top. Plunger 200 can representthe plunger of the present invention or other prior art plungers.Sensing the plunger is used as a programming input to achieve thedesired well production, flow times and wellhead operating pressures.Master valve 7 should be sized correctly for the tubing 9 and plunger200. An incorrectly sized master valve 7 will not allow plunger 200 topass through. Master valve 7 should incorporate a full bore openingequal to the tubing 9 size. An oversized valve will allow gas to bypassthe plunger causing it to stall in the valve. If the plunger is to beused in a well with relatively high formation pressures, care must betaken to balance tubing 9 size with the casing 8 size. The bottom of awell is typically equipped with a seating nipple/tubing stop 12. Springstanding valve/bottom hole bumper assembly 11 is located near the tubingbottom. The bumper spring is located above the standing valve and can bemanufactured as an integral part of the standing valve or as a separatecomponent of the plunger system. Fluid 17 would accumulate on top ofplunger 200 to be carried to the well top by plunger 200.

Surface control equipment usually consists of motor valve(s) 14, sensors6, pressure recorders 16, etc., and an electronic controller 15 whichopens and closes the well at the surface. Well flow ‘F’ proceedsdownstream when surface controller 15 opens well head flow valves.Controllers operate on time, or pressure, to open or close the surfacevalves based on operator-determined requirements for production. Modernelectronic controllers incorporate features that are user friendly, easyto program, addressing the shortcomings of mechanical controllers andearly electronic controllers. Additional features include: battery lifeextension through solar panel recharging, computer memory programretention in the event of battery failure and built-in lightningprotection. For complex operating conditions, controllers can bepurchased that have multiple valve capability to fully automate theproduction process.

Modern plungers are designed with various sidewall geometries (ref. FIG.10) and can be generally described as follows:

-   -   A. Shifting ring plungers for continuous contact against the        tubing to produce an effective seal with wiping action to ensure        that all scale, salt or paraffin is removed from the tubing        wall. Some designs have by-pass valves to permit fluid to flow        through during the return trip to the bumper spring with the        by-pass shutting when the plunger reaches the bottom. The        by-pass feature optimizes plunger travel time in high liquid        wells.    -   B. Pad plungers have spring-loaded interlocking pads in one or        more sections. The pads expand and contract to compensate for        any irregularities in the tubing, thus creating a tight friction        seal. Pad plungers can also have a by-pass valve as described        above.    -   C. Brush plungers incorporate a spiral-wound, flexible nylon        brush section to create a seal and allow the plunger to travel        despite the presence of sand, coal fines, tubing irregularities,        etc. By-pass valves may also be incorporated.    -   D. Solid plungers have solid sidewall rings for durability.        Solid sidewall rings can be made of various materials such as        steel, poly materials, Teflon, stainless steel, etc. Once again,        by-pass valves can be incorporated.    -   E. Snake plungers are flexible for coiled tubing and directional        holes, and can be used as well in straight standard tubing.

Recent practices toward slim-hole wells that utilize coiled tubing alsolend themselves to plunger systems. Because of the small tubingdiameters, a relatively small amount of liquid may cause a well toload-up, or a relatively small amount of paraffin may plug the tubing.

Plungers use the volume of gas stored in the casing and the formationduring the shut-in time to push the liquid load and plunger to thesurface when the motor valve opens the well to the sales line or to theatmosphere. To operate a plunger installation, only the pressure and gasvolume in the tubing/casing annulus is usually considered as the sourceof energy for bringing the liquid load and plunger to the surface.

The major forces acting on the cross-sectional area of the bottom of theplunger are:

-   -   The pressure of the gas in the casing pushes up on the liquid        load and the plunger.    -   The sales line operating pressure and atmospheric pressure push        down on the plunger.    -   The weight of the liquid and the plunger weight pushes down on        the plunger.    -   Once the plunger begins moving to the surface, friction between        the tubing and the liquid load acts to oppose the plunger.    -   In addition, friction between the gas and tubing acts to slow        the expansion of the gas.

In certain high liquid wells, fluid build up hampers the plunger'sdecent during the return trip to the bumper spring at the well bottom.Thus, wells with a high fluid level tend to lessen well production bydelaying the cycle time of the plunger system, specifically delaying theplunger return trip to the well bottom. Prior art designs have utilizedby-pass valves within plungers. These by-pass valves permit the fluid toflow through the plunger during the return trip to the bumper spring atthe well bottom. The by-pass valve provides a shut off feature when theplunger reaches the bottom. This open by-pass feature allows a fasterplunger travel time down the hole in high liquid wells. Although by-passvalves are manufactured to allow fluid pass through, optimization of theby-pass opening size for the valve is difficult due to variations inwell liquid loading. As well conditions change, different by-passopenings are required for optimization. The prior art solution tends theuse of a variety of bypass plungers, each with a different size orificeopening. Thus, the optimization of prior art plunger lifts in a highliquid well is difficult with a fixed size orifice by-pass design. Whenthe plunger falls slowly to the bottom of the well, it decreases wellefficiency. Plunger drop travel time slows or limits well production.Well production increases are always critical.

What is needed is a plunger lift apparatus whose orifice size can betuned to well conditions at the well itself and whose orifice size canbe quickly changed at the well site as well liquid loading conditionschange over time. The invention must function in a high liquid well, beone that can insure continuous efficiency during lift, drop back to thewell bottom quickly and easily and assist in increasing well productionby increasing lift cycle times. The apparatus of the present inventionprovides a solution to these issues.

SUMMARY OF THE INVENTION

The main aspect of the present invention is to provide a variableorifice by-pass plunger apparatus that will increase well productionlevels in a high liquid well.

Another aspect of the present invention is to provide a by-pass plungerapparatus with a by-pass orifice that can be easily varied at the wellitself to several different levels.

Another aspect of the present invention is to provide a by-pass plungerthat could efficiently force fall inside the tubing to the well-holebottom with increased speed without impeding well production.

Another aspect of the present invention is to allow for a plungerfunction by-pass valve to be shut off once the plunger reaches the wellbottom in order to provide for proper plunger return lift to the welltop.

Yet another aspect of the present invention is to allow for the plungerby-pass valve to be re-opened to its preset condition once the plungerreaches the well top.

Another aspect of the present invention is to allow for various plungersidewall geometries to be utilized.

Other aspects of this invention will appear from the followingdescription and appended claims, reference being made to theaccompanying drawings forming a part of this specification wherein likereference characters designate corresponding parts in the several views.

The present invention comprises a plunger lift apparatus consisting of atop section allowing for various sidewall geometries, an inner diameterallowing for liquid by-pass, and typically having an inside top holloworifice design (typically a standard American Petroleum Institute (API)fishing neck), and a bottom section containing a variable by-pass valveto allow fluid to flow through the valve and up through the top sectionduring the return trip to the bumper spring at the well bottom.

The variable orifice by-pass plunger (VOBP) of the present inventionallows more than one orifice setting in the by-pass valve. The VOBPcontains a variable orifice valve (VOV) that has a variable orifice thatcan easily be set to more than one position. When released from the autocatcher, the orifice will function to allow liquid to pass through theplunger lower valve section and up through the plunger top sectionduring its return trip to the well bottom. The well control system willrelease it to fall back into the well when conditions are satisfied.Depending on the high liquid well parameters, the VOV can be set tooptimize the VOBP return time to the well bottom, thus optimizing theproduction efficiency of the well. Once at the well bottom, the VOV isdesigned to shut off the by-pass feature when striking theaforementioned bumper spring. Upon its return trip to the well top, theaforementioned extracting rod within the lubricator will cause the VOVto re-open at its predetermined set condition.

The present invention assures an efficient lift-in a high liquid welldue to its design. The present invention also optimizes well efficiencydue to the fact that it has a field adjustable orifice to allow it toquickly travel to the well bottom.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 (prior art) is an overview depiction of a typical plunger liftsystem installation

FIG. 2 is a side perspective view of the variable orifice valve (VOV) ofthe preferred embodiment of the present invention.

FIG. 3 is a side perspective blow up view of the VOV of the preferredembodiment of the present invention showing all internal parts.

FIG. 4A is a side cross-sectional view of the VOV of the preferredembodiment of the present invention in the open (or bypass) position.

FIG. 4B is a side cross-sectional view of the VOV of the preferredembodiment of the present invention in the closed (no bypass) position.

FIG. 5 is a top cross sectional view of the inner wall internal to theVOV body cylinder, showing the three ball and spring fixed locations.

FIG. 6 is a cross-sectional view of the VOV body cylinder inner wall(ref. FIG. 5) and the inner variable control cylinder top surfaceratcheted (or set) in the mid orifice-bypass set location.

FIGS. 7, 8, 9 are side perspective drawings of the VOV showing theadjustment of the three VOV locations of the preferred embodiment of thepresent invention.

FIG. 10 shows side plan views of the present invention with varioussidewall geometries.

FIG. 11 is a side plan view of the present invention falling throughliquid within the well tubing.

FIG. 12 is an exploded view of an alternate embodiment.

Before explaining the disclosed embodiment of the present invention indetail, it is to be understood that the invention is not limited in itsapplication to the details of the particular arrangement shown, sincethe invention is capable of other embodiments. Also, the terminologyused herein is for the purpose of description and not of limitation.

DETAILED OF THE INVENTION

Referring now to the drawings, the present invention provides a variableorifice by-pass plunger (VOBP) apparatus (see item 1000 of FIG. 11) thatwill increase well production levels in a high liquid well. The VOBPcontains a lower section variable orifice valve (VOV) 200 (see FIGS. 2,3, 4, 10) that can be easily preset to several different levels, thepreferred embodiment having three set levels. The VOBP is designed to beset to an optimized by-pass orifice opening to efficiently force fallthrough liquid inside the tubing to the well-hole bottom. Thisoptimization of the orifice setting will optimize return-speed throughliquid and thus optimize well production. VOV 200 has an internalby-pass shut off mechanism, which will close the by-pass feature oncethe plunger reaches the well bottom. A shut off condition is required inorder to provide for proper plunger return lift to the well top.Concurrently, the plunger by-pass valve will be re-opened to its presetcondition once the plunger reaches the well top.

The top section of a VOBP can be designed with various aforementionedplunger sidewall geometries (ref. FIG. 10, items 20, 60, 70, 80) thatall contain a hollowed out core 47. The top collar of each type VOBP istypically designed with a standard American Petroleum Institute (API)internal fishing neck that is a well-known industrial design and istherefore not shown in detail herein. The spring loaded ball within aretriever and protruding outside its surface would thus fall within theAPI internal fishing neck at the top of the VOBP orifice for a smalldistance to a point. Wherein the inside diameter of the orifice wouldincrease to allow the ball to spring outward. This condition would allowretrieving of the VOBP if, and when, necessary.

The bottom section, or variable orifice valve (VOV) 200 is the primarypart of the present invention. VOV 200 easily attaches to the VOBP topsection, screws on for example. VOV 200 contains a variable by-passorifice to allow fluid to flow through the VOV and up through the topsection during the return trip to the bumper spring at the well bottom.

The VOBP of the present invention allows more than one orifice openingsetting within VOV 200. That is, the variable orifice can easily be setto one or more positions. When released from the auto catcher, theorifice will function to allow liquid W (ref. FIG. 11) to pass throughthe lower section (VOV 200) and up through hollowed out core 47 (seeFIGS. 10, 11) during its return trip to the well bottom. The wellcontrol system will release the VOBP to fall back into the well whenconditions are satisfied. Depending on the high liquid well parameters,VOV 200 can be set to optimize the VOBP return time to the well bottom,thus optimizing the production efficiency of the well. Once at the wellbottom, the VOV is designed to strike the aforementioned bumper springand shut off. Upon its return trip to the well top, the aforementionedextracting rod within the lubricator will cause VOV 200 to re-open atits predetermined set condition.

The present invention optimizes well efficiency due to the fact that ithas an adjustable orifice to allow it to quickly travel to the wellbottom. The orifice is thus field adjustable; it can be tuned at thewell site depending on well parameters to optimize well cycle times. Thehigher the well pressure and/or liquid loading, the greater the orificeopening can be set. This results in the ability to optimize the bypasssettings based on well conditions allowing the VOBP to fall back to thebottom in an optimal manner. This avoids having to have a variety ofdifferent bypass valves, with various manufactured orifice openings, atthe well site. The VOBP of the present invention provides the ability tofield adjust the bypass-settings as well parameters change over time.

The VOBP of the present invention basically is employed with thefollowing discrete steps:

-   -   1. The bypass setting is manually tuned for well loading        conditions (ref. FIGS. 7, 8, 9).    -   2. The VOBP is at the bottom of a well with liquid loading on        top of the plunger and with its push rod 25 set in a closed        bypass position (ref. FIG. 4B).    -   3. The well is open for flow at which time the VOBP rises        towards the well top to carry accumulated liquids out of the        well bore.    -   4. The VOBP reaches the well top, is caught within the        lubricator, and the extracting rod (ref. FIG. 1) strikes push        rod 25 to move it into a bypass (or open) position (ref. FIG.        4A).    -   5. The well flows for a set time or condition controlled by the        well-head controller.    -   6. The auto-catcher releases the VOBP after a set time or        condition as controlled by the well system controller.    -   7. The VOBP force-falls to the well bottom, its bypass setting        allowing liquid enter its bypass opening and optimize its fall        to the well bottom and thus optimize well production efficiency.    -   8. The-well plunger lift cycle starts again (step 2 above).    -   9. Periodically, an operator visits the well site and decides        whether or not to change the bypass setting for sizing the flow        through orifice, depending on the well liquid loading        parameters.

FIG. 2 is a side perspective view of the VOV 200 of the preferredembodiment of the present invention. VOV 200 is the bottom section ofthe VOBP. When the VOBP falls to the well bottom, push rod 25 bottomsurface 34 will strike the aforementioned well bottom bumper springcausing push rod 25 to move up into VOV 200 functioning to close thebypass function (ref. FIG. 4B). VOV 200 is shown with VOV body cylinder40 having VOV body cylinder orifice 43 set to one-third open due to theposition of variable control cylinder 26. Positioning of variablecontrol cylinder 26 can be adjusted through adjustment slot 29. VOVbottom cap 24 functions to contain all internal parts of VOV 200.

An alternate embodiment (FIG. 12) shows, the upper body end 440 securingthe control cylinder 2600 in a fixed position. The VOV body cylinder4000 rotates around the upper body end 440. Threads could provide thisrotation, cylinder pins 4011 could mount in holes 4010 in the body end440, or other design choices could be used. The slots 4015 areadjustably aligned with slots 4016 to provide a variable orifice. Hole4020 is aligned with a chosen hole 4010 to set the orifice. Sheath 441secures the cylinder 4000 to the upper body end 440.

FIG. 3 is a side perspective blow up view of VOV 200 depicting thepreferred embodiment of the present invention and showing all internalparts. The assembly of VOV 200 consists of the following parts:

-   -   a) VOV body cylinder 40 that is designed to have;        -   an adjustment slot 29 for orifice adjustment access.            Adjustment slot 29 provides tool 38 with access to control            cylinder adjustment hole 32;        -   four VOV body cylinder orifices 43 spaced at about 90°            apart;        -   internal threaded lower body end 20A to accept VOV bottom            cap 24;        -   internal wall 3 (ref. FIGS. 5, 6) to contain three springs            27 and three corresponding balls 28 all with a fixed            position and separated by about 120°; and        -   internal threaded upper body end 44.    -   b) Push rod brake clutch 21 consisting of two half cylinders 23        each containing annular grooves to contain annular push rod        brake clutch springs 23 and functioning to contain push rod 25        in either its open or closed positions.    -   c) VOV bottom cap 24 with external treaded area 24A to mate with        VOV body cylinder internal treaded lower body end 20A.    -   d) Push rod 25 having bottom bumper striker end 34 functioning        to move push rod 25 into a closed position once VOBP hits the        well bottom and having push rod closure end 37 with outer        closure ring 35 and rod slant surface 36 functioning to both        close against VOBP top section in its closed position at the        well bottom and also to move to an open position when VOBP lifts        to the well top; the aforementioned striker rod within the        lubricator will strike against rod top end 37 to move push rod        25 into its open position thus allowing the bypass function via        the preset orifice settings during VOBP movement back to the        well bottom.    -   e) Variable control cylinder 26 having external adjustment hole        32, four control cylinder orifices 31 which are spaced apart by        about 90°. Variable control cylinder top surface 46 has nine        preset position control half globe holes 33 located in groups of        three, each group about 120° apart and each half globe holes        within a group at about 20° apart. Control half globe holes 33        mate with balls 28 three at a time within each group 120°        spacing and 20° internal group hole spacing providing three        preset thru-orifice positions (full open, one-third open, two        thirds open) in each of the four thru orifices. The total        opening, or thru-orifice, is a function of the position of the        control cylinder orifices 31 with respect to the VOV body        cylinder orifices 43.

When VOV 200 is assembled, control cylinder orifices 31 align with VOVmain body cylinder orifices 43 such that the total thru opening will beabout 33%, 67%, or 100% depending on the positioning of variable controlcylinder 26 in one of its three set positions. Adjustment slot 29provides external tool 38 right movement direction TR or left movementdirection TL functioning to set variable control cylinder 26 in one ofits three positions via control cylinder adjustment control hole 32. VOV200 is geometrically designed to have a fluid/gas dynamic type shape toallow it to quickly pass to the well bottom while allowing fluids toenter its orifice and pass through the top bored out section of theVOBP. Thus the VOBP will return to the bottom with an efficient speeduntil it comes to rest on the bottom sitting or on a bumper spring,which will strike its push rod and close its bypass function.

FIG. 4A is a side cross-sectional view of VOV 200 of the preferredembodiment of the present invention with push rod 25 in the open (orbypass) position. VOV 200 treaded upper body end 44 mates with uppersection treaded end 41 (ref. FIG. 10). When VOV 200 arrives at the welltop, the aforementioned striker rod within the lubricator hits push rod25 at rod top end 37 moving push rod 25 in direction P to its openposition. In its open position, the top end of push rod 25 rests againstvariable control cylinder 26 internal surface. Brake clutch 21 will holdpush rod 25 in its open position allowing well loading (gas/fluids etc.)to enter the open orifice and move up through top section center bore 45allowing the VOBP to optimize its decent to the well bottom as afunction of the bypass setting.

FIG. 4B is a side cross-sectional view of VOV 200 of the preferredembodiment of the present invention and similar to FIG. 4A but with pushrod 25 depicted in its closed (no bypass) position. When bottom bumperspring striker end 34 hits the aforementioned bumper spring at the wellbottom, push rod 25 moves in direction C to a closed position as shown.In the closed position, rod top end 37 with its slant surface 36 closesagainst treaded top section end 44 and is held in the closed position bybrake clutch 21 thus allowing VOBP to be set in a closed bypasscondition to enable itself to rise back to the well top.

FIG. 5 is a top view of the inner wall 3 (ref. section 5-5 of FIGS. 3,4A, 4B) internal to VOV body cylinder 40 showing the three ball andspring fixed locations. Three ball springs 27 and three balls 28 (ref.FIG. 3) are located within bored out holes 4 spaced in an annularposition around inner wall 3 and about 120° apart.

FIG. 6 is a cross-sectional view of the VOV body cylinder inner wall 3(ref. FIG. 5) and the inner variable control cylinder top surface 46ratcheted (or set) in the mid orifice bypass-set-location. That is, ofthe possible three preset control half holes 33 within variable controlcylinder top surface 46 locations, the thru orifice is set to the midbypass location. Thus shown is one of the three ball springs 27, andball 28 located within one of the fixed internal set holes 4. Movementof variable control cylinder 26 (ref. FIG. 3) is in either direction TRor TL, which ratchets and fixes the bypass total thru-orifice opening toa set location.

FIGS. 7, 8, 9 are side perspective drawings of VOV 200 showing theadjustment of the three possible VOV locations of the preferredembodiment of the present invention. FIG. 7 depicts external tool 38within adjustment slot 29 and in leftmost position P1. In position P1,variable control cylinder orifice is aligned with the VOV body cylinderorifice such that the thru orifice is fully open position 50. FIG. 8depicts movement of external tool 38 in direction TR to mid-point P2setting. In this mid-point P2 setting, the thru orifice is nowtwo-thirds open position 51. FIG. 9 depicts further movement of externaltool 38 in direction TR to its rightmost position P3, which has the thruorifice in its one-third open position.

FIG. 10 shows side views of the VOBPs of the present invention withvarious aforementioned sidewall geometries; each VOBP depicted in anunassembled state with respect to its unique sidewall geometry topsection and a common VOV 200 bottom section. Each top section typicallyemploys a construction with a standard American Petroleum Institute(API) internal fishing neck. Each top section also has hollowed out core47. Each bottom section is the previously described VOV 200 shown in itsfull open (or full bypass) set position. The bypass function, aspreviously described, allows fluid to flow through during the returntrip to the bumper spring with the bypass closing when the plungerreaches the well bottom. The by-pass feature optimizes plunger traveltime in high liquid wells. Each VOV 200 has internal treaded end 44,which accepts top section treaded end 41 to unite both sections. Shownin FIG. 10 are VOBPs with the following geometries:

-   -   a) VOBP 300 with top section 60 having spring-loaded        interlocking pads 61 in one or more sections. The pads expand        and contract to compensate for any irregularities in the tubing        thus creating a tight friction seal.    -   b) VOBP 400 having top section 70 with brush sidewall 71 which        is a spiral-wound, flexible nylon brush section to create a seal        and allow the VOBP 400 to travel despite the presence of sand,        coal fines, tubing irregularities, etc    -   c) VOBP 500 having top section 20 with solid sidewall rings 22        and cut grooves 30 for durability. Solid sidewall rings can be        made of various materials such as steel, poly materials, Teflon,        stainless steel, etc.    -   d) VOVP 600 having top section 80 with shifting rings 81 all        individually separated at each upper surface and lower surface        by air gap 82 for continuous contact against the tubing to        produce an effective seal with wiping action to ensure that all        scale, salt or paraffin is removed from the tubing wall.

FIG. 11 is a side plan view of VOBP 1000 of the present inventionfalling, in direction F, through liquid W within the well tubing 9. VOBP1000 is shown fully assembled with a solid sidewall top section 20 (ref.FIG. 10) and bottom section VOV 200 (ref. FIGS. 2, 3, 4) that is set into a full open position. Liquid W enters VOV body cylinder orifice 43,moves up through hollowed out core 47 in direction D and out throughVOBP 1000 top section 20. VOBP 1000 thus moves through liquid withinwell tubing 9 and outer casing 8 in an efficient manner with VOV bodyorifice 43 set to an optimum opening position.

The VOBP of the present invention allows initial bypass set tuning atthe well site, allows future resets if necessary within one singleplunger, and thus assures well production optimization in high liquidgas wells.

It should be noted that although the hardware aspects of the VOV andVOBP of the present invention have been described with reference to theexemplary embodiment above, other alternate embodiments of the presentinvention could be easily employed by one skilled in the art toaccomplish the variable bypass aspect of the present invention. Forexample, it will be understood that additions, deletions, and changesmay be made to the variable orifice valve (VOV) with respect to design,adjustment mechanisms to set the orifice openings (such as ratchet typeadjustments etc.), various orifice opening settings, orifice geometricdesign other than those described above, and various internal partdesigns contained therein.

Although the present invention has been described with reference topreferred embodiments, numerous modifications and variations can be madeand still the result will come within the scope of the invention. Nolimitation with respect to the specific embodiments disclosed herein isintended or should be inferred.

1. A variable orifice bypass plunger comprising: a plunger body havingan internal channel to provide a fluid path out a top end of theplunger; a plunger bottom having an inlet to the internal channel; saidinlet having a variable positionable closure means functioning to permita user to fix the closure means to a desired opening for the inlet; saidplunger bottom further comprising a push rod means functioning to movefrom an inlet open position with the push rod means extended downwardfrom the plunger bottom, and functioning to move upward to an inletclosed position upon an impact on a push rod means bottom; and whereinthe desired opening for the inlet remains unchanged regardless of amovement of the push rod means.
 2. The plunger of claim 1, wherein theplunger bottom has a threaded connection to the plunger body.
 3. Theplunger of claim 1, wherein the variable positionable closure meansfurther comprises an outer inlet body member with an inlet hole and arotatable control cylinder mounted therein, the rotatable controlcylinder having a hole in a closure wall, wherein a rotation of therotatable control cylinder varies the opening of the inlet by alignmentof the inlet body member inlet hold and control cylinder hole.
 4. Theplunger of claim 3, wherein the rotatable control cylinder furthercomprises a top surface with engagement holes to receive spring loadedengagement means functioning to set the rotatable control cylinder atthe desired rotation.
 5. The plunger of claim 4, wherein the controlcylinder further comprises a tool hole to receive a tool to rotate thecontrol cylinder.
 6. The plunger of claim 5, wherein the outer inletbody member further comprises a slot to receive the tool and a push rodclutch brake assembly to hold the push rod in either its open or isclosed position.
 7. The plunger of claim 4, wherein the spring loadedengagement means further comprises a recess in the outer inlet bodymember which receives a spring and a ball which fits into the engagementhole of the control cylinder.
 8. An internal by-pass plunger comprising:a plunger body having an internal conduit with an inlet at its bottomand an outlet at its top; a plunger bottom having a push rod movablefrom an extended position which leaves the plunger body inlet open, to aretracted position which closes the plunger body inlet; said plungerbottom further comprising a side opening and a rotatable cage mountedinside and the cage having an alignable hole with the side opening;wherein changing the alignment of the side opening and the cage holevaries an inlet to the plunger body inlet; and wherein said rotatablecage further comprises a releasable lock assembly to maintain a rotatedposition until a user changes it.
 9. The plunger of claim 8, wherein thepush rod has a clutch assembly connection to the plunger bottom tomaintain the push rod in a set position.
 10. The plunger of claim 8,wherein the releasable lock assembly further comprises a recess in theplunger bottom which receives a spring and a ball, the ball locking intoa recess in the cage.
 11. The plunger of claim 8, wherein the cagefurther comprises an adjustment hole to receive a tool.
 12. The plungerof claim 11, wherein the plunger bottom further comprises a slot toreceive the tool.
 13. A variable by-pass plunger comprising: a plungerbody having a fluid channel and an inlet thereto at its bottom; avariable by-pass assembly connected to the bottom; said variable by-pasassembly having a rotatable outer casing with a side hole; wherein aninternal fixed cage has a side hole to align with the outer casing sidehole to provide a variable orifice to the bottom inlet; and wherein apush rod is mounted in the variably-pass assembly to open and close thebottom inlet.
 14. A variable orifice valve (VOV) adapted to connect toan internal by-pass plunger, said VOV comprising: an upper neck having athreaded connection for a plunger bottom; said VOV having a lower endwith a clutch broke for'a centrally mounted push rod; said push rodhaving an upper valve head to seal an outlet of the upper neck in aretracted position, and open the outlet in an extended position; saidVOV having an external housing with an inlet hole; a rotatable cagemounted in the external housing; and wherein a hole in the cage ismoveable in relation to the external housing inlet hole to provide avariable orifice for the outlet.
 15. The VOV of claim 14, wherein thecage has a locking means functioning to temporarily set the cage in adesired position until a user changes the position.
 16. The VOV of claim15, wherein the cage has an adjustment hole for a tool, and the externalhousing has a slot to receive the tool.
 17. The VOV of claim 16, whereinthe locking means further comprises a recess in the external housingwhich receives a spring and a ball, the ball slidingly engaged with arecess in the cage.
 18. A variable orifice valve (VOV) for an internalby-pass plunger, the VOV comprising: a housing means functioning toprovide a connection at its upper end to a lower end of a plunger; saidhousing means having a lower end with a clutch means functioning tosupport a push rod means in a set position; said push rod meansfunctioning to open and close the upper end; and a cage means mounted inthe housing means functioning to rotate to a desired position so as toalign a cage hole with a housing hole, thereby providing a variableorifice to the upper end.
 19. The VOV of claim 18, wherein the cagemeans has a spring loaded catch engaging the housing means, therebyproviding a constant rotation position of the cage means until a userchanges it.
 20. The VOV of claim 19, wherein the cage means has anadjustment hole to receive a tool for rotational adjustment.